Open start and there is a folder known as startup, if you put Internet Explorer inside this folder (for example by copy and paste it), then during startup, it will open it.Basically what ever you put in this folder will open during startup.

Boot in Safe Mode:

Open Run command as previously described

Type MSConfig

Click on Boot tab

Tick Safe boot in Boot option

Select Network

Click Apply and OK

Reboot your system

Your system will boot in Safe mode with Networking. You may now try and open Windows Store and should not see any errors.